How to raise pH in fish tank with Baking soda- [Complete guide]

In this article, I will teach you how to raise pH in fish tank with baking soda.

When it comes to maintaining a fish tank, pH plays an important role due to this reason. Due to this reason, It is necessary for fish keepers to maintain a stable pH.

Most aquarists make the mistake of altering the pH value of a fish tank without having much knowledge about it.

Hence it is better to know about pH, how it works, how can you alter the pH using various ways and so.

baking soda
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You don’t have to go in-detail about pH but, having basic knowledge about pH should be fine.

The reason why you should be worrying about pH in an aquarium is that it directly affects the water quality inside your aquarium.

Most of the beginners are not aware of these things and they usually end up making a mistake. Due to this reason, fishes often suffer and die.

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Altering pH is quite easier if you have a basic knowledge about its working chemistry. If you remember you have already studied about pH in your school days.

To make changes with aquarium water in pH with baking soda there are few things you should be knowing!

But don’t worry, I have got this covered for you.

Let dive right in!

What is pH?

pH stands for potential of Hydrogen. In simple words, It is a scale that is widely used in the field of chemistry to specify the acidity or basicity level within an aqueous solution.

Usually, the pH scale is logarithmic and this scale inversely indicates the concentration of hydrogen ions.

At standard conditions of around 25° C Aqueous solutions, less than 7 are acidic, and solutions greater than 7 are basic or alkaline in nature.

The scale is from 0 to 14 in which 7 is neutral. Solutions can also be greater than 14 with very strong alkalinity or even lesser than 0 with very strong acidic.

Measurement of pH is done with various methods like

  1. Making use of pH meter
  2. Using pH color changing indicator
  3. Measuring pH Using Glass Electrodes

Researchers use pH meters and glass electrodes in labs to perform various tests. But in my opinion, pH color-changing indicators work perfectly fine as they are available easily and are quite cheap in price compared to other testing equipment.

In water chemistry, pH plays a crucial role. For instance, a pH of 5 is 10 times and a pH value of 4 is 100 times more as the pH value decreases the more acidic the solution is.

It is also a problem if you are having two different fishes that are suitable with two different pH like 6 and 8. This is the reason why you should be choosing suitable tank mates for your fishes.

If the tank mates are suitable with similar pH them you don’t have to worry at all.

How does pH work in freshwater?

It is very simple and easy to understand! For example, Distilled water or pure water has a neutral pH (7) which means when you add an acidic solution to pure water the pH value decreases.

Similarly, when you dissolve pure water with a base or alkali the pH value will be greater than 7 which is more basic.

As per Wikipedia, when you expose pure water to air it mildly becomes acidic. This is because water absorbs carbon dioxide from the air and is then converted into bicarbonate and hydrogen ions.

Water hardness Influencing pH level in fish tank water while using baking soda

Most people don’t talk about it. To change the pH level it is crucial to have the right softness or hardness of the water.

Before you try changing the pH of fish tank water with baking soda It is important to understand its depending factors.

People fail to understand the science behind the hardness or softness of water that is dependent on the pH value.

Fishes are comfortable at a certain level of water hardness or softness too much variation in the water hardness will cause distress and an uncomfortable environment.

Moderating pH once you have a proper hardness or softness of water is quite easy. Sometimes if the water is too hard varying pH goes hard and shows instability in pH.

Being a fish keeper it important for you to understand its working and the chemistry behind it.

Water chemistry is a fun topic if you learn about it. Also, It is very easy for you to maintain an aquarium if you are aware of all the things like these.

Most of the aquarists don’t really know the dependency of pH on the hardness or softness of water. If you find your water to be hard then most probably it consists rich amount of minerals.

As you can see, hard water contains a large number of minerals and you will find a lot a lesser amount of minerals in soft water.

The minerals present inside hard water have a direct effect on the pH level. The harder the water the higher the pH will be.

You might have heard that rainwater is usually soft water as it has a very less amount of minerals and this is the reason why rainwater is called the purest form of water.

Water driven from the lakes contain a high amount of calcium and is mostly hard water.

Basically, It all depends on the source of water is coming from.

What is Water Hardness?

Water hardness is the amount of dissolved calcium, magnesium, and other minerals present inside the water. You will notice a high quantity of minerals in hard water.

The hardness of water is a problem when it comes to boilers, cooling towers industries. If you notice a lack of foam formation when soap is used in water it is very likely that the water is hard.

It is most likely that your tap water is hard and this is because they add cleansing agents like chlorine inside water while supplying to prevent pipes from damaging.

There are few varieties of fishes that require hard water while others require soft water.

How to test Hardness of water

Testing the hardness of water is important because it directly affects your aquatic pets.

Hence in this section, I will let you know about how to test the hardness of the water in your fish tank.

Testing water is quite simple and easy you don’t need any types of equipment to test it. This can be done right at your home.

Steps to test the hardness of the water in your fish tank at home

  1. Take an empty transparent bottle, fill about 1/3 portion of it and then add a few drops of liquid soap or liquid detergent depending on its availability.
  2. Shake the bottle thoroughly until mixed well.

Here is the interesting part! If you find the absence of bubbles and if the water looks cloudy and milky then this water is hard.

Soft water has bubbles when you mix it with detergent or soap. They usually lather when you rub them with water.

Note: Remember to use Basic soap that is free of dyes, perfumes and detergents

In this modern technology, Detergents are made to be suitable with hard water. This is the reason why using basic soap is important.

However, using the above method is not accurate. It might not give you proper readings.

Because of this reason, I will teach you how to test Hard water using a hard water kit.

Test kits are available in most of the stores or else you can buy them from amazon given down below.

Once you get this kit, It’s time to test your water hardness. Test kits include a color chart and testing strips.

Steps to test Hardness of aquarium water using Hard water testing kit

  1. Collect your fish tank water in a clean and transparent glass.
  2. Next, Insert the hard water testing strip for several seconds and then remove it.
  3. You will find the color of the strip to be changed depending upon the hardness of the water.
  4. There will be a chart provided with the testing kit take it out and compare its color with the strip.

Also, note that you should never perform a hard water test in running water as it might provide inaccurate readings.

If you are not comfortable testing the hardness of aquarium water you can get it tested in a 3rd party lab.

Different varieties of fishes are comfortable with different hardness levels of water. Depending on the fish you are keeping in the aquarium check if it is suitable or not.

If you find too much variation in the data It is time to soften your aquarium water.

How to convert Hard water to Soft water?

If you find your tap water is hard then you should consider softening the water before adjusting pH in the aquarium.

Water softeners are present in the market that will soften hard water easily. Working with water softeners is simple they will help remove the minerals that contribute to the hardness of the water.

Using too much hard water for your fish tank is not recommended as fishes are quite distressed and found to be uncomfortable.

If you find it hard to use water softeners you can try Boiling water as it reduces some sort of hardness as most of the minerals settle down.

Once you do this you can try using a siphon to take out the top of the water and get the partial soft water

By using water softeners you will find these advantages

  • It prevents white spots in the filtration system and pipes.
  • Makes your fishes more comfortable and helps regulates pH easily.
  • Helps eliminate minerals and calcium

Raise pH in Fish tank with Baking soda

There are various different ways to raise pH and raising pH in a fish tank with baking soda is one among them.

If you find your pH to be high and wish to lower it down. Here is an article on lowering pH in an aquarium using safe and natural methods.

In this section, I will give an overview of its working and explain how you can raise pH with baking soda in fish tank.

Here is an Infographic Check it out!


What is Baking soda?

Baking soda also known as sodium bicarbonate is a type of salt that is commonly found in most houses.

It is a type of salt in which a sodium cation and a bicarbonate anion are present. People often make use of baking soda for various purposes like cooking, baking, pest control, Alkalinity/pH increase, etc.

Here is a fun fact about sodium bicarbonate

“Sodium bicarbonate is found in such personal care items as toothpaste, where its mild abrasiveness helps remove surface stains from teeth”

As per the National Lab of medicine, Baking soda is usually in the form of a white crystalline powder or granules. It is odorless and has saline and a slightly alkaline taste.

Working of Baking soda to raise pH in a fish tank

When you mix up baking soda a.k.a sodium bicarbonate with water you will observe both endothermic and exothermic reactions taking place.

This reaction gives rise to carbonic acid which will eventually start releasing CO2 and water weakly ionizes.

As you all know, sodium bicarbonate is a base when it reacts with water it becomes more alkaline raising pH in the aquarium.

Here is how the salt hydrolysis takes place!



Formation of bubbles is found when you react baking soda with water.

Thus, when you add baking soda to your fish tank water you will notice raise in both pH and alkalinity that will eventually improve stability.

Most people even use baking soda in their pools to raise the pH or alkalinity of the pool water.  It is quite cost-effective and is easily available at most of the stores.

Steps to Raise pH in fish tank with baking soda

  1. First of all, It is important to note the pH value of your fish tank water. You will find the pH value depending on the type of water you are using and its source. It will be usually around 6 to 7.8.
  2. Now, It’s time to test with sample water and this is because you will get an idea of the amount of baking soda you should be using.
  3. Take half a liter of water in a clean beaker and let it sit for a few hours. Next, test the pH of this water and note it down.
  4. Add 1/4 teaspoon of baking soda inside the sample water. Mix It well and wait for 15-30 mins.
  5. Now, test the pH of the sample water and check if it makes any difference.

Once you do this, you can now make changes by raising your pH in a fish tank.

We recommend you add the amount of baking soda depending upon the test results you conducted. In Most cases 1/3 teaspoon of baking soda for a 4-5 gallon of water is fine.

However, there are various other factors like water hardness, impurities present inside water, chlorine, etc that depend while the change in pH.

Water chemistry is very vast and people are unclear about this topic due to this reason we recommend you to test before you try out yourself to ensure safety.

Note: To ensure you raise the pH without hurting fishes remove them before you add baking soda

Once you do this, retest the pH of your fish tank water to compare the value of pH you are willing to raise. Consider waiting for at least  6 to 8 hours letting the pH get stabilized.

You can turn on the aquarium water filtration system to improve the circulation process.

Now, I hope you know how to raise pH in fish tank with baking soda.

Also Read: How to Lower pH in Aquarium with vinegar?

Thanks for reading!

What do you think? Share your experience on raising pH with baking soda and the best ways you use to raise pH in the comment section down below.

2 thoughts on “How to raise pH in fish tank with Baking soda- [Complete guide]”

  1. Great article.
    Compared to other methods of raising ph in my fish tank, the use of baking soda is one of the cheapest and easiest for fish-keeping advocates.

  2. Thank you for your help with raising water ph, especially for providing the amount per 5 gal.
    With RO Water ph was 6.5. I have 40 gallon tank, mixed 2/3 t through filter, will retest in the morning.
    I thought better to be conservative than to over treat .

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